Beneath The Surface
by Skitzylou
Summary: An old friend is moving back to New York and April couldn't be more excited! After an incident at the beach, the secret about the turtles is revealed and Don quickly falls for their newest ally. However, it quickly comes to light that she may be hiding something big from her friends. As they try to find out what's going on, reports come of a mermaid being spotted in the Hudson.
1. Surprise?

**Author's Note:** This story has been posted on may AO3 account as well. For those of you who may prefer to read from there, my username is the same as it is here. Also, for any following my OTHER story I'm soooo sorry I haven't updated in so long T^T Anyway, I hope you guys enjoy my newest fic. Oh, and you can blame my friend Indy for giving me the dumb idea to put my mermaid OC in the frickin' TMNT universe. THANKS A LOT JACKASS! ...I love you.

 **Cover art was made by my friend Fordandra on tumblr! Please go check them out!  
**

* * *

 **Chapter 1: _Surprise_** ** _..._** ** _?_**

April couldn't be more excited for this week. Work was going great at Channel 6, her favorite group of boys wasn't in any immediate danger, an old friend of hers was coming back to New York soon, and she had a whole day planned to show her band of turtles a nice little beach she knew of not too far out of town. It was a nice little spot she'd found with a friend a long time ago, completely secluded and almost impossible to get to. Because of its difficulty, almost no one ever bothered to go there and even less knew it was even there. It was perfect! Everyone was on board and ready to go, even Splinter gave consent for his sons to go. However, he insisted he wouldn't be coming along.

"I will stay here and watch our home. Besides, I have a few soaps I'd like to catch up on and do not wish to get sand in my fur. Last week, Jessica was about to confess to Brian while Jeremy was just about to reveal that he was really her twin brother all along!" The simple fact the old rat watched soap operas at all still amazed her, but for some reason…wasn't all that surprising.

The boys themselves couldn't be more excited…and nervous. It was rare they could go anywhere without having to hide or stick to the shadows. They watched basketball games from above where no one could see them, viewed parades from storm drains, and most often had to wait for a movie to come out of DVD or be pirated if they wanted to watch. Mikey kept going on and on about being able to use his collection of surfboards, make a huge sandcastle, and maybe bury Raph in the sand. Raph had similar ideas in mind, but was also just looking forward to being out in the sun. They almost never got the chance to do that. "Are you _absolutely_ sure we won't be seen by anyone out there?" Leo asked for the hundredth time over the phone. The blue leader was ever the overly cautious mother hen. For the hundredth time, O'Neil assured him it would just be them on a private beach, unreachable by normal human means. Most people would probably die just trying so it had been blocked off by police years ago. Some friends in the NYPD pulled a few strings and called in a few favors to get them access for a day. They would be the only ones allowed.

"And…what about this friend of yours? The one coming down soon? Don't you need to meet them?"

"Relax, Leo. Nikita won't be coming for another week or so, I checked. I sent her an e-mail letting her know I'd be gone if she decided to stop by early. There's no problem! I promise you, nothing bad is going to happen down there. Now get some sleep, I'm picking you boys up early tomorrow so we can beat the morning traffic." She hung up the phone, recalling how her old friend was soon to be her new roommate and how that all transpired in the first place before sleep could claim her mind.

* * *

"Hello? Nikita? Who are- I think you may have the wrong…! Oh my god, Nixie! Hi!" The pitch of her voice shot up a few octaves, becoming girlish and squeaky. April sat up immediately in her seat, a big smile spreading across her face. "I haven't heard from you in ages! How are you doing? Yeah, I'm working at Channel 6. Yeah, can you believe that?" She could hear the joy in her friend's voice on the other line. "Well I've been working there a while so it's not really news to me, girlie. Uh huh. So what's up? Apartment prices out here? Um…they can get pretty expensive, why? …What?! No way, seriously?!"

April had to get up and start moving, no longer able to keep still and bounce her foot. The four teens around her looked up curiously from their spots in the lair. Normally April's calls were short and sweet, either about work or…yeah no, usually work. They'd never heard her so girlishly excited. It was like listening to one side of a high school girl's phone call with her BFF.

"Well, you could always room with me. Yeah! My old roommate moved out a year or so ago and I've been looking for a new one anyway, you'd be perfect! Oh? Oh, okay. Hey, we can talk more about it later when you're not busy. See you soon, bye!" When April hung up the phone she still had that smile, looking to the boys with an excited glimmer in her eye.

"What was that all about, angel cakes?" Mikey was closest, having leaned closer to try listening in. His chin rested on the arm of the couch, baby blue eyes wide as he stared and tilted his head at her curiously.

"An old friend of mine, this girl who lived next door when I was a kid, her name was Nikita and she's moving back to New York to finish school! I haven't talked to her in so long! Once, she came by the lab you guys were made in because her dad got called in to work but they didn't have enough time for a babysitter and our parents were old friends." She grinned at the old memory. "Little Nixie was a lot younger than me and somehow got her hands on Splinter. Dad almost had a heart attack." The memory was happy, but bitter sweet.

"What'd she do to him?" Raph turned, eyeing their Hogosha. It was understandable for him to be a bit hostile at the mention of their father in some strange human's hands pre-mutation. Being the protective older brother he was, she assumed he was determining whether or not this girl could be a threat today.

"Oh come on, she was just a baby and she didn't know what she was doing. Besides, all she did was hold him and giggle. My dad was just glad Splinter didn't bite her." She took her seat again, crossing one leg over the other. "Sachs was mostly worried about contamination while my dad was concerned about what his friend would do if his daughter got hurt on his watch." There was audible venom in her tone at the mention of that snake. She was so glad that monster was behind bars.

"I would not have bitten her, Miss O'Neil." The old rat walked into the room, a soft smile on his face. It seemed he regarded the incident just as fondly as she did. "I think I remember young Nikita, very sweet for such a young child. I will admit, I was fearful of being handled too roughly by such a young child at first, you know how young ones can be at that age." He chuckled, glancing to his boys and perhaps recalling on something the boys did as babies. "Then again, I raised four very energetic young boys, not a small girl."

"Yeah, she's always been slightly…different." April sighed. "We were close up until she had to move away when her dad's job got transferred. Their whole family had to move with him. I tried keeping in touch but after a while everything just…got so complicated. Honestly, I'm surprised she even remembered me or still had my cell number! I'm pretty sure I changed it a few times at one point…"

"It sounds like the two of you will have much catching up to do." The old rat smiled knowingly. Did he know something she didn't?

"We do, Master Splinter. That we do."

* * *

Not long after that the two started texting back and forth constantly, calling when they could about how everything would work and what to do. Apparently her old friend had acquired her number by calling family members. When calling her old number had gotten her someone else, rather than give up she went through relatives to find her current contact information. The girl was nothing if not completely and immovably stubborn when she wanted to be. If they weren't talking about being roommates then they were catching up with one another's lives. Nikita, or Nixie as she was fondly known, was coming back to go to school in the state in which she'd been born. She planned on finding a job while she was there to help pay rent and had lived a fairly quiet life on the west coast up until now. The girl spoke of how much she missed it back east and wished she hadn't moved away and lost touch.

April apologized herself for not staying in better contact, telling of her own college days and life as a news reporter. She left out mention of her boys for the time being. Nixie didn't need to hear all of those details just yet. As much as she trusted her friend, it had been so long! Who knows if she'd be able to keep such a secret now? Besides, it wasn't exactly her secret to tell in the first place.

The woman sighed as she stared up at the ceiling in bed. Tomorrow was going to be a good day. She was spending time with her boys, her friend would be another day closer to flying over and nothing was going to ruin it. Everything was good.

• • •

Everything was not good, it was so not good! They got to the beach and there was someone there! Someone was on the beach. Their _private_ beach. And someone was sitting under an umbrella and staring out at the waves crashing on the shore. Who had even managed to get down here? Even she couldn't get down past the rocks without the turtles' help. Thinking back, she wondered how she'd ever gotten down there as a kid.

Behind her the boys stood stock still, muscles tensed and all senses on high alert. There weren't many places they could hide and if they tried to leave the way they came they ran the risk of whoever was out there seeing them. The rocks were high and uneven. Getting up or down took immense concentration and a sharp eye, too slow for an escape. The only cover close enough was too far for them to sprint to without also risking getting seen. They were basically trapped. Leo leaned down and whispered harshly in her ear. "April, I thought you said we'd be the only ones here!"

"I thought we would," she hissed back. "Nobody knows about this place except for me and Vern! …Wait here." She took a few steps forward, trying to get a closer look at the person on the beach. There had to be a way she could get this girl to leave without exposing the turtles and blowing their secret.

It must be a girl, based on the small curves and the olive, cropped tube swim top she wore with a pair of cut-off jean shorts. There was a pair of dark sunglasses on her face, hiding her eyes and a pixie short brown hair cut with sky blue streaks on the bangs. On her right shoulder was a black, tribal lotus blossom. The closer she got the more familiar the girl seemed. Where had she seen this girl before? April was sure she didn't know anyone with dyed hair like that, or with a tattoo on their arm. She flinched as the girl finally turned her head to look in her direction, lifting the sunglasses to reveal pink-purple eyes. That's when it all clicked. _Oh…SHIT…_

"Nixie?!"

"April!" The biggest, happiest grin spread over the teenager's face as she raised a hand to wave at her. "Hey!"

"Hey! What the hell…I mean, w-what are you doing here?" April smiled, coming over and trying to put on a happy-to-see-you-omg face. Maybe she could give the boys enough time to hide or make a break for it.

"I managed to finish up early so…I figured I'd come down now! I got your message about going you to the beach with your friends and thought I'd surprise you and meet your friends!" Nikita leaned to the side, trying to peek around her. "So, you gonna let me meet these friends of your-"

"No!" April quickly moved to block her view. "I mean...how'd you get here? Isn't it like…dangerous? A-and how'd you know we'd be here?"

The teen just laughed, getting up frown her towel to walk around her. "Hello, I showed you this spot, remember? And you mentioned the secret cove, and last I remember that's what we called this place." She was smaller, lighter on her feet and easily ducked under the older woman's arm. Curse her fast reflexes! "What are you worried about anyways? Come on, if they're friends of yours I'm sure it'll be fine! I'm practically your sister…after…all?"

 _Shiiiiiiit..._ April turned around too late, Nixie already getting a good look at four. Large. Teenage. Humanoid turtle boys standing off to the side near the rocks, each holding some kind of beach item under their arms and clad in nothing but their masks and a pair of swim trunks with ninja weapons on their person. "Um…heh…surprise?"


	2. At The Beach

**Cover art was made by my friend Fordandra on tumblr! Please go check them out!**

* * *

 **Chapter 2: _At The Beach_**

"Okay hang on and gimme a sec here. So…what you're saying is these," Nixie gestured to the turtles, "are your friends?" The six of them all sat together under the umbrella and on a blanket April had placed on the sand for them. Nikita sat between April and Mikey, her knees pulled up to her chest as she looked at each one of them with an unreadable expression. Was she upset? Was she internally freaking out? Was she scared out of her mind? She seemed to be taking it surprisingly well, no screaming or fainting, just wide eyes and silence. A new record for not freaking out at least. This wasn't exactly how April had been expecting this all to go.

"Yeah…" April tried to remain calm, tapping her heel against the ground. She'd already apologized numerous times to the boys and in her minute of minor hysteria only moments ago, moved between them and Nixie to hopefully dissuade her from attacking or screaming. The best case scenario she'd been expecting was maybe another Casey or Vern incident, maybe fainting like she herself had, worst case being what happened with the NYPD. But Nixie? She rolled with it almost immediately. Of course she was shocked but for the most part she didn't scream, she didn't try to fight them or call them freaks, she didn't even ramble on with stupid questions like Vern when meeting Raph. She was handling this like a champ.

Instead she just held up a hand to silence April, took a deep breath, then sighed and calmly asked for an explanation. Which she'd been given.

"And they're also ninjas who happen to be mutated turtles who were the actual ones to beat up the Foot Clan and that weird sky thing?" They gave her a nod. "And said mutated turtles were mutated in that lab your dad worked in from whatever stuff they put in 'em?" Another nod. "…Alright, I only have one more question."

"What's that?"

"Why did you pick Renaissance painter names for them, but Splinter for the rat?" Nixie motioned from her left to her right, pointing with both hands from the turtles to an empty space, staring at April with a raised brow. "Like seriously, you could 'a given him an Italian sounding fancy name and all like the rest, but you name the guy after a piece of wood stuck in your foot?! I just don't get it!" She threw one hand up in the air before ending with arms crossed over her chest in a light huff.

April stared at her incredulously. "A-are you serious?! I was what, twelve? I don't know!" On the other side of her friend Mikey fell back on his shell in a fit of laughter. Raph just shook his head and chuckled while Donnie giggle snorted and Leo tried to hide his amused smile. He didn't want to admit it, but this girl seemed alright. Meeting a group of freaks like them and all she has to say is why their father's name didn't match the Italian painter theme.

"Well now that we have that out of the way I need to ask our new...friend here, a more serious question." Leo scooted closer, staring into the girl's strange eyes. They were a pinkish-purple, getting more pink as it got closer to the pupil. Very odd for a human. She looked back at his more simple blues and for a split second, he forgot what he needed to say.

"Leonardo, right? What is it?" Her voice broke through whatever spell he came under and he blinked, clearing his throat.

"Can we trust you to keep our secret? Master Splinter will want to ask you this himself, but in case it wasn't obvious we must remain an absolute secret. People can't know we exist."

"Well, the entire NYPD knows about us."

"Mikey, not helping." Leo hissed.

Nixie giggled, absently waving a hand to get his attention again. "I'm no stranger to the need for secrets, Leonardo. Some are necessary in the world we live in today." The look in her eyes had him wondering what she might be hiding, but he still trusted her words. She seemed sincere and that would have to be enough for now. Their father would have to be the final decision once they got home. "I will keep your secret, don't worry."

For a few minutes he stared at her face, her eyes, subtly took in her scent to analyze as much as he could. No fear, her heartbeat sounded steady enough, gaze never left his own. When he felt he had enough information the turtle pulled away and nodded his head. "Alright."

"So she's clear?" Mikey sat up, baby blue eyes wide and with a huge grin claiming a large portion of his face. Even April seemed relieved at Leo's decision. It was understandable, this girl being an old friend after all. When the eldest gave his nod to confirm, the youngest quickly lifted their newest ally into a strong hug. "You hear that, baby cakes? You're all clear!"

"For now!" He snapped. "We still have to notify our father." Leo frowned.

Michelangelo just rolled his eyes and went on hugging her. "We still got a few hours before its time to go home, bro. Don't be such a stick in the mud." His eyes fell on the girl cradled in his arms. She was smaller than April, light and easier to move around. Her eyes were spellbinding and the cute, airy giggle she had when he picked her up made him want to hear it all day every day. He liked this girl. "What say you and I head into the water, doll face?" His tone was teasing as he set the girl on the sand and took her hand. Her smile fell at his words, making him pause. What was wrong?

"Mikey, I don't think that's such a good-" She never got to finish her sentence before she was snatched up again.

"Come on girly; if you're gonna hang with us turtles you gotta get a little wet now and then." Raph lifted the girl over his shoulder as he walked by, much to April's horrified expression. Mikey followed, but with less enthusiasm. What was April so worried about? He looked up at Nixie on Raph's shoulder, her eyes wide and almost in some state of shock.

Donnie was the first to notice something incredibly wrong. He may not have his goggles on to scan her vitals but the sudden wave of fear that came from Nixie was hard to miss. That, paired with April's look of panic and worry it slowly started to click together. Leo soon took notice, getting up from where he'd previously been sitting so calmly. As the two got closer and closer to the waves, that was when Nixie started struggling. Something was wrong. The lankier turtle rushed to catch up, April hot on his heels and yelling at Raph to stop and put her down.

"No! No no nononononono. Please n-no!" Nixie kicked her legs, pushed at his shoulder. She didn't want to start hitting him but nothing she did seemed to faze him and all he did was chuckle and bounce her a bit on his shoulder, shifting her angle. Mikey didn't seem so sure about this anymore.

"Bro, I don't think she's havin' any fun." The younger brother looked between the girl and his brother. Not having fun was an understatement. She looked more like she was getting kidnapped than being playfully messed with by a friend.

"Chill out, it's just the shallows." The bulkier turtle shrugged, lifting the girl over his head.

"Raphael! Stop!" April ran ahead and planted herself right in front of the turtle, stopping him in his tracks just before they could reach the water. "You gotta put her down, right now."

"What? We're at the beach, Apes. You gotta go in the water at the beach. Relax, I wasn't gonna toss her in or nothin'. I'll put her down when- hey!" Before he could finish Donnie had snatched the girl from his grasp, now holding her against his chest like a mother might hold her child. Raph gaped at him before growling, reaching to take her back before April smacked his arm. It didn't hurt, but the action itself had him pull back, looking at her strangely.

"She's afraid of water, Raph!" April scolded. "You can't just drag her out to sea like that! She can't even swim!"

"Seriously?! It's just a little water! It ain't gonna kill her!" The red turtle glared, turning his full attention to the smaller female before him.

"That's not the point!"

While he and April argued, Donnie made his way back to shore where their stuff sat in the sun and shade. The girl was trembling against his plastron, arms wrapped tight around the back of his neck while her legs did their best to cling to his sides. In his head he couldn't help but picture a koala. He had one arm looped across her back and the other propped under her rear to keep her stable. "It's okay; you don't have to go out there if you don't want to. Raph didn't mean any harm. Just watch, he'll come back after cooling down and apologize in the most passive aggressive way you've ever heard. He's just a bit of a hothead, but he means well. Hey, are you alright?" The tall turtle gave her a light bounce, leaning her back so he could get a look at her face. He gave her a little smile to maybe cheer her up?

Around her eyes was a bit puffy and the extra shine in her eyes suggested she'd almost cried. Poor girl was terrified. "I-I'm okay…th-thank you, Donatello." Her voice cracked a little and she sniffed, but otherwise she seemed to be calming down. That was good.

Don sighed, giving her an awkward smile. It just dawned on him that he was holding a girl in his arms. A very cute girl. He cleared his throat, swallowing awkwardly. "D-don't worry about it! And uh…you can call me Donnie, i-if you want." His voice squeaked and raised an octave at one point like he was going through puberty all over again. Embarrassing, but he felt he managed to not be a total loser…right?

"Alright, Donnie." Nixie smiled just as awkwardly as he did. Don took a better look at her face while she was so close. Her eyes were very strange, definitely not something you'd expect on a human. He wished he'd brought his goggles to analyze them better. Purple eyes were an extremely rare mutation and seldom did the person live very long. But these, these were purple and pink, an impossible anomaly. Perhaps magenta or a fuchsia? No, those seemed too much. Well…not impossible obviously since they were right in front of him. They weren't colored contacts either, as he could see her pupils expand and contract. What made them that color? A million genetic possibilities ran through his mind. Her cheeks were getting a little red.

"D-Donnie? You can put me down now, w-we're here."

"Huh?" He took a quick look around, seeing Leo staring at him with a raised brow and a sly smirk. His face turned a burning burgundy. "O-oh, right! Sorry." Becoming quite flustered, he set the girl down before taking a few steps back. "My apologies."

She lightly shook her head, giving him a soft smile that made his heart skip a beat. "It's fine. Thanks for helping me out with your brother." Without saying much else, she took a seat on the blanket near Leo and grabbed a book from her bag.

 **• • •**

For the rest of the day things were peaceful. No further incidents arose. Well, at least none like before. Nikita did jump away when a wet water bottle was tossed to her _and_ she ran from Mikey when he tried to hug her while soaking wet, but that was it. All in all it turned out to be a good day.

After drying off and finally getting his hug after that, Nixie and Mikey found a spot not too far from the others to build a few sandcastles. Mikey did most of it. Despite all of his attempts the fellow teen simply refused to get wet, even just a little bit. April joined them soon after. "Hey April, is she always this…stubborn when it comes to gettin' wet? I mean I get not being able to swim or being afraid of it, but not getting even a little wet?" The orange turtle glanced up from his building to look at their friend, collecting shells to decorate their castle.

"Yep, for as long as I've known her she's never liked getting wet. She wouldn't do any of the swimming for gym class." April pat down the side of a tower. "Once, a guy who had a crush on her splashed her for fun and she ran off. They don't know where she went but apparently after class he went to apologize and she slapped him."

Mike's head recoiled and his eyes widened as he looked from April to Nixie and back. "Wait, she slapped him got getting her wet?"

The woman nodded. "Yep. She was pissed! I still think it was a bit much but I understand her reasoning. It's a pretty big fear of hers so whether the kid meant any harm or not splashing her must have been a pretty big insult, especially if the brat's excuse was having a stupid crush. I don't care if you think the girl is cute, you don't act like a jerk."

"True that, girl." Mikey nodded. He glanced up again, a smirk growing on his lips. "Speaking of crushes, I think Don likes your friend."

"What?"

"Yeah, look!" The teen nodded in the direction of the others. As April turned her head to look, she just barely caught Don staring at Nikita. He was right. Now that she thought about it, he'd been looking at her almost all day, on and off. When she was reading her book earlier he sat right next to her and just…watched. When he eventually got up to join his brothers in the water he still continued to keep an eye on her every now and then.

April smirked right back. Mikey may not have seen, but she did. "She's been watching him too." Nix had been watching him all day. The most notable being when he was in the water and stood up, drenched. Poor girl's face turned so red she immediately hid behind her book. Leo had long since abandoned trying to be stoic and responsible for having some fun in the sun of his own. The only one who'd been around to see was her. Maybe Donnie, but that boy was blind as a bat without his glasses.

"Whoa, wait, seriously?!" Mikey's face lit up, snapping over to Nixie again. By now, Donnie had turned away to avoid getting caught and took to stretching out a few joints. Sure enough, their new friend had picked up where he'd left off, dropping all of the shells she'd gathered into the sand as her cheeks slowly started to match her eyes. Before Don could look back at her she turned her back and started hurriedly picking up her shells, only causing his brother to blush as he got a nice view of her ass in those shorts of hers. "Oh man, this is too good. You think they're a good fit?" He looked at the two watch each other from afar.

"Maybe. I haven't seen Nixie in a long time, but she doesn't seem like she's changed much. She's shy, really soft with others. If she ever heard someone hurt her friends she'd totally kick their ass too. We'll have to see how they go but I think it'd be nice to at least see them try. They're both nice kids who need someone just as patient in their lives. It could work." April watched with a wistful smile. "It's gonna be a bitch to get either of them to ask the other out though. God, that's gonna be such a huge pain!" She groaned, rolling her eyes and going back to the castle.

* * *

Nixie ended up getting a ride with them, seeing how she'd taken a taxi to get from the airport to the beach. She took the passenger seat in the van, spending most of the ride either chatting with April in the driver's seat or leaning over her chair to talk to the boys. Before they got home she made every single one of them give her their numbers so they could hang out and talk again. Like Donnie predicted, Raph apologized for freaking her out while also calling her a total crybaby.

"It's okay, Raph. You didn't know and…honestly I overreacted a bit. I'm sorry about that. Friends?" The girl's face was upside down from where she leaned over her seat, giving him that cavity-inducingly sweet smile of hers.

"We'll see, princess." He smirked. "Still gotta earn that title, just like everybody else."

"M'kay!" She smiled wider and popped back to talk with April again.

Donatello continued to steal glances as much as he possibly could. Mentally he was telling himself this was stupid and to not get attached to some girl he didn't even know, even if she was April's friend. Their dad still had to give her the okay and the entire time he hardly even talked to her! He just…stared at her like some kind of…some kind of…nerd! _She must think I'm such a freak._

* * *

"Later guys! Get home safe, we'll see you later." April waved as the brothers made their way through the alley to the manhole closest to their home.

"Hey, it was nice meeting you guys!" Nikita leaned out of her window, smiling at them. "You said I gotta meet your dad still, right? Splinter?"

"We'll be careful, April." Leonardo bowed to their Hogosha, turning to look at Nixie. A smile tugged at the corner of his mouth. She was so childish. "Yes, we'll have to let him know that you found out about us. I'm not sure what he'll say. He might-"

The girl just rolled her eyes and waved him off. "Oh pshaw, it'll be fine. Just tell him I say hi and I can't wait to meet him. Oh! And ask him if he remembers the Cheese-Its! Does he remember those? I don't but apparently I fed him Cheese-Its once and-"

"Nixie! They have to get home!" April laughed, pulling at the girl's arm. "And so do we, now get your butt back in the van."

"Fiiiiine! Just gimme a sec, okay?" The teen whined, trying to pull herself free while waving her free hand at the turtles. "Bye Mikey! Bye Raph! Bye Leo! Bye Donnie! Hey, text me so I know you guys got back okay, alright? I- ack!" She got cut off as April finally pulled her in and started to roll up the window so she wouldn't attempt another coup.

"Later, sweet cakes!" Mikey winked at the girls and blew a kiss as they left, jumping down into the sewers. "Heh, I like her friend. She's pretty cool."

"She's alright." Raphael shrugged, hiding his smile.

"Yeah…" Donnie coughed, fixing his glasses. He was glad the darkness hid the blush on his face.

Leo sighed. _She seems nice._ He didn't want to admit it and get his hopes up, but he really hoped she passed the test with their father.

* * *

Nixie hummed happily as she and April drove away. "I really like your friends, Ape."

"Good to hear, Nix." The woman smiled.

"Especially Donnie, he's cute."


	3. Meeting The Sensei

**Chapter 3: _Meeting The Sensei_**

To Leonardo's surprise, Splinter made no rush in meeting Nikita. In fact, he almost seemed to expect her to find out at some point. "Huh, I'm surprised it happened so quickly," he'd mused before waiving off his son's protests. He insisted on letting her have time to unpack her things and settle in with April. "She does not need four teenage boys running around while she tries to unpack. Leave her be while she finds her space." In the meantime, the boys got stuck with extra training and were allowed to call and text as much as they liked, but no visiting as punishment for being seen. Friend of April's or not, they still broke a rule. The rule.

Leo couldn't figure out why his father was being so lenient with this one though, none of it made any sense to him. Vern had been a special case only due to dire circumstances and Casey got points for being fun to mess with, but both were okayed as an emergency measure. April was the whole reason they were even still alive and had been in danger. She was family. Why did this new girl get treated so...casually? What made her different? What was their father doing?

Mikey for one was glad to have a new friend, especially a human friend! It was like a dream come true! A human that wasn't April _and_ she was their friend? Score! He texted her the second they got home and continued to do so late into the night. He asked what her favorite color was, what her hobbies were, what kind of music she liked, her favorite snacks and foods, what movies she liked; anything and everything he could think of. Her favorite color was any of the cool colors, so blues and purples and greens, but mostly purple. Mike made sure to tell Donnie that one right away, taking great delight in how his brother became flushed and chased him off. Knowing he had something new to tease his brother with was also a plus.

Her hobbies mostly included cooking or drawing and she admitted to hoping for a job at a restaurant or maybe a cafe while she was here. She insisted on keeping some things to herself, others she said depended on her mood. When he asked if she had a boyfriend she just sent him a laughter emoji with "single 4 life". He smiled, peeking in on his older brother again. "Hey bro, she's totally available."

"Who's what, Mikey?" Don wasn't paying attention. Some of the hydraulics were broken in the truck again. He'd been working on them all morning.

"Nixie, she's totally single bro. I asked for you. So, when you two gonna smooch?" There was a loud clang and some mild cursing from under the truck. While the lanky turtle scrambled to get out from under the metal mess, his sibling took that as a cue to get a head start and run!

Next to Mikey, Donnie messaged her the most. He didn't bombard her with questions about what color she liked or what her favorite animal was, instead he usually asked her about her day or what she was doing. At first her messages came off as rather formal and almost robotic, nothing but short answers with perfect punctuation. After a peek at Michelangelo's messages it seemed that was normal for the beginning. As she got used to talking with them her texts became a little more silly and relaxed, filled with classic texting shortcuts and little emotes or smiley faces.

Nixie would tell him how she was applying for different jobs close to the apartment or along her route to school, whether she'd had lunch or not yet and if an interview felt like it went well or if she was worried she messed up. Through these messages he found that despite her fear of water, she loved stories about mermaids and just about anything having to do with aquatic life. She loved Pirates of the Caribbean, The Little Mermaid, some show called H2O he'd never heard of, and many others. If it had the ocean or mermaids, chances were she'd love it. Her mother was apparently a marine biologist and so she was always surrounded by stories and treasures from the deep. It fascinated him how one could be so interested in a world while being blocked off from ever experiencing it themselves by a phobia. Donnie once asked if she wanted to become a marine biologist as well, but she quickly declined and instead mentioned she'd rather become a chef or a baker. He told her he thought she would make a great chef someday. Her response was that he hadn't even tried her cooking yet and a laughing emoji.

When they didn't text about their days and occasional interests, Nixie seemed to take great pleasure in reducing him to a fit of snorts and giggles. She sent him any and all science puns or jokes she knew off the top of her head or found simply browsing the internet. The girl also sent him links or screenshots of posts she found funny or related to science that she thought he might like. Some he knew or had seen before, but he smiled at each one. Just the thought that something made her think of him made his chest swell with pride and he saved each and every one to a special folder.

As he learned of her interests, he tried doing the same. He sent a few recipes that were based on science experiments or had an ocean theme or just that he thought she might enjoy and sent them her way. Her immediate response was to send him heart emoji's and try it as soon as she got home. Once April made a joking complaint that she was surrounded by too many treats.

 _ **Don, maybe try sending her something that isn't a cookie next time?**_

There was a photo attached with a picture of their fridge, a whole shelf filled with leftovers of the sent recipes. Some were labelled with a post-it for April to bring over ASAP. Donnie just smiled.

 _ **Never. :D**_

A few hours later he got another picture, a selfie of April munching on yet another science-related recipe with an overly-proud-of-herself Nixie photo bombing in the back.

 _ **I hate u T_T 3**_

 _ **Love u 2 Ape ;p  
**_

* * *

After a month of waiting, Splinter finally called for the girls to come over for dinner. Everyone was nervous to say the least. Each of the boys had gotten to know Nixie in their own way and neither could find anything dangerous about her. Mikey couldn't stop talking about showing her around the lair and how he was going to hang out with her all the time, provided their father gave her his blessing. Raph just shrugged and rolled his eyes, staying out of the conversation. He didn't mind the new girl, but he felt like there was just something…off. Leo felt the same way but was far less vocal about his suspicions. So far, there was nothing that led him to believe whatever she might be hiding was dangerous to him or his family. Yet.

Donatello was a mess of nerves, almost tempted to lock himself in his lab and pretend he was extremely busy on more projects during their visit. The crush he'd been hoping would just fade away had only gotten worse through their talks, and he couldn't be sure if her replies were a sign she felt the same or if it was all just her being…nice. There was no such thing as love at first sight, he refused to believe that. An attraction to a cute girl maybe, but he couldn't fall so quickly. The thought of talking to her again though? That turned him to stone. Texting was fine. He could fix a typo or take a few minutes to come up with a smooth response, but seeing her face to face again? He felt like he was going to have a panic attack. Face to face he could mess up, trip over his words and say something stupid that he couldn't take back! What did he do? Did he act like everything was normal? Did he try flirting? He had no idea what to do; the closest thing he ever had to experience with talking to a girl before was April and she was like their mom or their sister! If not for the fact they'd be here soon he would have asked her for advice. _Maybe if I don't screw up too bad tonight I still can?_

"Angel cakes! Baby doll! You're here!" Michelangelo's voice and the giggles of a certain female human snapped him out of his nervous pacing and set his heart racing. Oh no, they were already here! Don turned his head to see his younger brother scooping each girl into a big hug, the smaller of the two moving her arms out of the way to avoid something in her hands from getting crushed.

"Careful monkey, you almost smashed my cookies!" Nixie giggled again, now trying to keep the turtle from swiping the sweets. "Hey! These are for after dinner, no nibbling."

"Aw come on, just one? Please, baby doll?" Mikey clasped his hands in front of his face, giving her his signature puppy dog eyes.

"No, and no amount of pouty faces will change my mind!" She rolled her eyes. "Hey April, where should I put these anyway?"

"Over here, follow me." Leo came from the kitchen, giving the girls a gentle smile. There goes that honor boy charm. "It's nice to see you again, Nikita."

"You too, Leo." Nix smiled right back, her soft smile setting Don's face ablaze.

Oh god they were already here. Donnie went rigid when those heliotrope colored eyes landed on him, his stomach filling with butterflies. It felt like time slowed. He had his goggles on his head this time, but he was unable to move, frozen in place and incapable of pulling them down for a quick scan. She looked just as radiant under the lights in the lair as she had under the sun on the beach. Was that possible, looking like an angel under two very different light sources? Nixie smiled at him, glancing away to whisper something to April. Did her cheeks change color just now? Maybe he was seeing things. No way could a girl like that blush from seeing a guy like him.

A hard slap to the back of his shell snapped the turtle out of his trance, making him cough and fumble to push up his glasses. He turned, finding Raphael standing behind him. "You like her, bro?" Raph glanced at his lankier sibling.

"I...p-perhaps..." Don glanced down, fiddling with his gear. "Sh-she's an attractive female a-and our hormones aren't the most stable at this point in our lives. Also, we don't exactly have much experience with humans let alone girls so-"

"Donnie."

He flinched, looking down to hide his face. "Y-yeah..." There was no use fighting it if even Raph could see. Had he really fallen so hard so quickly?

"Just be careful, alright?" Raph pat his shell. "I'm glad you like a girl, just...I don't want ya t'get hurt if things don't work out..."

* * *

Splinter looked up from a cup of tea as the girls walked in with Leo to put the cookies in a spot that Mikey would _hopefully_ be unable to find them. "Ah! Is this Nikita?" He stood up, setting his tea down and walking around the island for a closer look. The girl in question snapped her head up almost immediately, eyes going wide. A warm smile touched his lips. "Ah, I think it is. I'd remember those eyes anywhere."

Her face lit up like it was her birthday. She dropped the cookies into April's hands and she bolted over to the giant rat, almost tackling him in a hug while squealing like a little girl. **"Splinter!"**

The old rat caught her with a slight grunt, wrapping his arms around her small form and chuckling. She was just as bright as he remembered. His other sons came over to peek inside, having heard the squeals. "It's so good to see you again, young one. How have you been? I haven't seen you since you were just a baby."

"I'm good! And I haven't seen you since…April showed me the pictures and videos?" Nixie pulled away just to look up at his face. She had only been a baby when she met them as lab animals; it was no surprise she wouldn't remember. "Oh! Did Leo tell you about the Cheez-its thing? My dad said I gave you Cheez-its. Is it true?"

The old rat laughed. "Yes, you did indeed try to feed me Cheez-it's when you were little." He smiled, ruffling her hair. "It is very good to see you again, my child."

Leo and the others stared strangely from the background. They'd never seen their father smile that way towards anyone but them and maybe April. He did it when he looked at old baby photos or things from their childhood, that reminiscent smile thing that parents did when they thought about their children when they were still little. Now he did it to Nixie. Why? Speaking of the girl, she herself looked like she couldn't be happier. It was like she was meeting an old relative she hadn't seen for years or visiting a beloved grandparent. She was giggling like a child and giving their father the biggest hugs. It was strange yet…sweet.

Mikey took a tentative step over. "So…does this mean she's cool, dad?"

Splinter looked up from the girl clinging to his chest to his son standing beside him. "Hm? Oh, of course!" The old rat chuckled. "Young Nikita is most certainly _cool_ , Michelangelo. I remember more about her than you think." He smiled, the girl in his arms pulling away to giving a quizzical glance. "Her family has always been good friends to the O'Neil family and she has always been like a sister to our April, so I see no reason to think why she wouldn't be a part of our family as well."

"Wait, if she's already cleared then why couldn't we see her for a month?" Donnie pipped up, keeping his eyes on their father. He knew the second he looked at the girl he would start to fumble and falter, so he kept his focus away.

"Because, Donatello, you were seen. Luckily it was only Nikita, but you must always be vigilant, even on vacation. What if someone else had been on that beach?" He raised a brow at them. "Besides, she needed time to acclimate to her new home."

Nixie twitched a little at his last comment, glancing at the old rat with wide eyes. Don stopped breathing the second his eyes wandered to her. Even when she was making such ridiculous faces, she was beautiful to him.

"I doubt it takes a month to adjust to a place like New York, Master Splinter." Leo crossed his arms over his chest, looking rather exasperated.

"Perhaps, but the Hashi seemed too much in this case. Extra stealth training and limited contact with your new friend seemed appropriate." The rat chuckled. "Now, if you boys would excuse us I would like to speak with her in private for a moment. Come with me, Nixie." He looped his arm with hers, walking off to another room while the girl looked back at them in confusion.


	4. Getting To Know You

**Chapter 4: _Getting To Know You_**

When Splinter and Nixie rejoined the group they were walking side by side, the girl smiling like and laughing. What had they talked about? Just a few moments ago she looked terrified and now she was joking back and forth with him. When the boys tried to investigate, Splinter ordered them to back off.

"I merely calmed her nerves on a few issues and clarified some questions she had, nothing you need worry about." He waved them off, leaving to make everyone some tea.

Mikey took the moment of freedom to scoop Nixie into his arms for an even bigger hug than when she came over. He lifted the human teenager off her feet, squishing her between his chest and arms while smooshing his cheek against hers. "Did you hear that, Nix? You're one of us now!" His laughter was contagious, sending her into her own fit of giggles as he danced in a silly circle while she tried her best to hang onto his neck. "Oh! I have GOT to give you the grand tour, babe!"

"Don't you have to make dinner?" Leo raised a questioning brow. Even as he tried to seem in charge, the corner of his mouth turned up in the hint of a smile.

"Oh! Right!" He sighed dramatically. "Bummer, lovely lady. Hmm…who could possibly show you in my place?" The orange ninja tapped his chin, holding the girl with one arm. "Ah! Donnie boy, why don't you show our princess around, hm?" He winked, grinning wide when his brother choked on his juice box.

"W-what? Y-you want me? Uh…" Donnie looked at Nixie and froze for a good minute, juice box falling to the floor before frantically looking for his two other siblings who'd chosen that exact moment to make themselves scarce. "B-but what about…uh…c-can't Raph...?" He rubbed at the back of his neck, admitting defeat. "Um…s-sure! Uh…I-I'll show you around…i-if you want."

"That sounds great, Donnie!" The girl hopped down from Mikey's clutches and half bounced over to his side. "Lead the way." Her hands stuffed themselves in that Avengers Hawkeye hoodie of hers. She dressed like a tomboy, clad in superhero t-shirts and a pair of bootcut jeans that were ripped along the bottom edges from getting stepped on all day for who knows how long. This girl was a nerd's dream. No matter what she wore, to him she was stunning.

"R-right." He motioned for her to go ahead, his other hand ghosting over her back. Did he touch her? Did he not? What did he do?! The genius turtle glanced back just in time to see all three of his brothers give him a thumbs up with April standing amongst them like a proud mom. A small growl rose from his throat. They planned this. He mouthed _"I hate you"_ at them before looking back to the human girl at his side, giving the least awkward smile he could muster. Did it work? When she looked back with that sugar sweet smile of hers his heart did a front flip in his chest, fluttered around his ribcage, and melted all at once. This girl would be the death of him for sure.

* * *

Nixie glanced back at April just before they turned a corner, getting a thumbs-up from her and a reassuring smile. That was good, right? She wouldn't give her a thumbs-up like that if she didn't have a chance, right?

 _A few nights ago, having tried out yet another recipe from Don and sat down to watch a sappy movie with April from their childhood the girls were relaxing on the couch of their apartment. The Princess Bride, one of the many fairytales Nixie always loved. She sighed, munching on some popcorn as she leaned on her friend under the old faded blue blanket they had draped over their legs. "You think we'll ever find guys like that?"_

 _"Like that?" April rose a brow, smirking down at her friend._

 _"Uh huh. You have no idea how much I'd just die if I met a guy who started saying something like_ "as you wish" _whenever he wanted to say I love you."_

 _"Mhmm…" The woman smiled knowingly as she popped another piece in her mouth._

 _"Isn't Don just so dreamy?"_

 _"Don?"_

 _Nixie paused, going stiff beside the reporter. "Oh fuck…"_

Ever since then, April constantly teased her about her crush while also coming back with any and all information she could about what she could do in order to get closer to her ninja turtle crush. Things that he was interested in. She found herself asking her mom more about the details of her research, talking to her dad about all the science behind medicine he could tell her without making her nauseous. She looked all of this up on her own too, her search history overflowing with physics and chemistry while still retaining the occasional cooking video. She'd always liked science, grew up around it with her Marine Biologist mother and nurse father. It made jumping into the articles and lectures on biochemistry and robotics easy and if she was honest, kinda fun. She had a whole folder of experiments she'd found that she wanted to try with him someday. For safety reasons, she tried to avoid anything with water.

Her fingers fiddled absently with lint and loose strings in her pockets as she tried to not only pay attention to the tour, but calm her nerves enough to figure out a topic that wouldn't be out of place. It wasn't like she could just blurt out a random thing about quantum physics she read on the internet without it seeming incredibly out of the blue and just…weird. What did she do what did she do?!

"This is uh…well it's pretty much my lab. It's also connected to what we call the garage? Um…Raph likes working on some of the vehicles in there with me, believe it or not. We salvaged a motorcycle a while back during a run-in with some Foot soldiers so he's been fixing it up and making a few tweaks. I've been trying to figure out what to do about the weight problem, since some of the parts aren't exactly made with our uh…dimensions in mind after all so…" Donnie continued on, his voice bringing her full attention to him. His cheeks were flushed a slight burgundy color as he adjusted his glasses on his face, looking into the room he was trying to show her. _Oh no he's so cute._

The second he turned back to her she snapped her head away, looking about the room. She wasn't blushing was she? Please _please_ don't notice if she was! Her eyes landed on a table filled with unfinished projects and contraptions. "Did you make these?" Just like that, her attention was pulled away again and her nerves settled a little. Talking about something he made and liked was a good topic, right? Just focus on what April told her, be yourself. Learn about him. Learn what he likes. _Chill out, Nixie._

After all, she wasn't even sure if he liked her back or if they'd work out. God, what if he didn't like her that way? Could he? Maybe he'd prefer something with a few more scales? Okay, that's a dumb thought. Nixie rolled her eyes mentally. Like him knowing _that_ would make any of this better. If he really wanted something with more scales, a tail wouldn't be the trick; he'd probably want an actual reptile. Maybe a reptile mutant girl would appeal to him more, not some weird human girl with weird eyes. _And I'm not even human at that…not really._

Her diversion worked at least, Donnie making his way over and explaining what some of the gadgets were or what they were supposed to be. Nixie kicked herself out of her mental funk, pushing any and all self-resentment aside. When she asked him about the science behind each object he seemed to relax, falling into his element. He practically glowed. The smile that came on his face, the spark in his eyes, the enthusiasm in his voice as he explained each of his contraptions and inventions to someone who at least managed to follow most of it. When he did come to something she didn't understand she asked him to explain more, usually getting it with the simpler explanation.

 **• • •**

"So, your mom is a Marine Biologist?" The tour long forgotten, Donnie sat in his skateboard chair while she sat on a wheeled stool across from him, messing with an old Rubik's cube.

"Uh huh, and dad is a nurse at a children's hospital. He has to be really careful though." She furrowed her brow, turning a few of the sides. Don found her expressions adorable.

"Why does he need to be careful?" He rested his chin in his hand, watching her work at it. He'd solved these a million times over and had at least five more lying around somewhere in this mess or in his room. Every move she made he knew the right way to solve it and he couldn't help but smile when she made the right choice or even the wrong one. It was just interesting to watch her.

"Water allergy. He has to be careful around the stuff." She turned the top row to the left, grinning wide and holding it up to him. "Look, I got a side!"

"Oh, that must be pretty bad. I can't imagine what that's like." Donnie looked at the side she finished, smiling back at her. Her excited enthusiasm and that bright smile from completing just one side made his chest ache. "That's a great job! Have you done this before?"

"Kinda, but I usually give up by now." Nixie looked it over, trying to figure out her next move. Why was he so scared of talking to her again? It was…surprisingly easy.

"Is uh…that why you're afraid of water? Your dad's allergy?" Don glanced down at his own hands. Those cubes suddenly looked so big in her hands, while in his they always seemed too small. What would her hands look like if he held them?

She paused, looking at the cube. Her face filtered through different emotions, contemplating…something. "Kinda…it's part of it."

"Do you want to talk about it?" He moved his chair closer. She shook her head. "Okay, I won't make you tell me." The turtle smiled as she lifted her head to look at him again. He stared right into her eyes. God, he could stare into those eyes forever. Her face, her eyes, everything. He wanted to hold her close and never let go. But he didn't. She didn't, no couldn't see him that way. He was a mutant turtle, unacceptable by human standards and she was the most beautiful girl he'd ever seen. She was way out of his league.

"Hey Don, we ah…we should probably go back with the others. They'll be wondering where we went off to by now." Nixie nodded back towards the center of their home. "Comin' with me?"

"Y-yeah." Donatello snapped out of his thoughts, standing up. "You uh…you can borrow that, if you want? I have a lot of them." He smiled nervously.

The girl's cheeks turned a little pink, eyes blinking up at him with her lips in a little o. "R-really? Thanks!" She smiled wide, clutching the little puzzle box to her chest. The sleeves of her hoodie covered most of her hands, only the tips of her fingers poking out the top. It was adorable.

The two got up, Donnie moving to walk ahead and lead the way. He heard the light tapping of her sneakers on the stone floor of their home and along the metal pipes, rushing now and then to keep up with his longer stride. Part of him wanted to walk faster to hear those quick little taps more. Part of him wanted to slow down and let her keep pace. Another part just wanted to pick her up and carry her around like a child with a new doll. There was another set of quick tapping before he felt small fingers wrap around his pinky-index finger. His heart nearly stopped. The warmth from those soft tiny fingers slid further and wrapped around his palm as much as they could. For a moment he paused, his pace slowing as he processed what to do. He analyzed what he should do, what reaction he might get from each response.

It was the little squeeze she made on his hand that shut his mind up. Don't think too hard. Don't over analyze until it's too late. Just do. He let out a shaky breathe, closing his fingers around her hand. That's how he rejoined his brothers and April, hand in hand with the little ball of instant sunshine.


	5. Tall Tails

**Chapter 5: _Tall Tails_**

Back at the apartment, after dinner was done and everyone went back home, April would _not_ shut up about Nixie and Donnie. She wanted to know everything. If they kissed, what they did, were they a thing now? It got to the point Nixie had to cover her mouth just so she could get a word in. Once the hand was over her roommate's lips she just gave her an undignified humph. Only after giving a muffled promise to shut up for five seconds was it removed.

"Ape, honey, chill. Nothing happened. We didn't kiss, we aren't dating…yet-"

"I knew it!"

"Shut up." She jabbed a finger at her. "We're not a couple and we just talked about some of his projects and other stuff we liked. That's it. Oh, and he let me borrow one of his Rubik's cubes." The girl pulled the partially finished box out of her pocket.

"…That's adorable. Admit it, this was amazing. How are you not internally screaming right now? You held hands with a guy you're totally crushing on!" April placed her hands on her hip, giving the girl a coy smile. "Come oooon~, just admit it. We're in the seclusion of our own apartment, the guys won't hear you. Mrs. Winston might but she's half deaf and wouldn't remember tomorrow anyways."

Nixie purses her lips, turning one of the sides back and forth in her hand. She stared at it for a while, a steady silence creeping up between them while April continued to stare her down. No amount of hoping she'd drop it would make it happen. That woman was relentless. "…Promise no judging?"

"Girl, I was there for your Naruto Bleach Inuyasha ninja anime demon OC weeaboo phase. I think I can handle you going a bit nuts over your mutant turtle crush." The reporter shrugged, moving her arms to cross them over her chest.

Nixie sighed, setting the cube off to the side before taking a deep breathe. She grabbed a nearby couch pillow, plopped it on her face, and screamed. Her feet tapped rapidly on the ground before she jumped up, pillow falling to the ground as she paced the room, hand running through her hair.

"Oh my god I was so nervous while he was showing me around and I couldn't really focus on everything so I was also trying to figure out a subject that wouldn't sound too out of place, ya know? And then we went to the lab and I asked about his inventions and he started talking about them and oh god he was just so…cute? Like his eyes had this sparkle in them and his smile…good god his smile and I swear he was just…just…glowing?! Oh god and we just talked for so long about his inventions and a bunch of science stuff and then we started trading element puns and it was just so _so_ easy to talk to him! I wanted to talk to him forever, just be there with him and never leave and I wanted to tell him every secret I ever had, even the super embarrassing ones you hold over my head aaaaall the time, and have him just…accept everything! Because I felt like he would! And he asked about my mom's work and then I told him how my dad was allergic to water?"

"Yeah?" April egged her on, listening intently to every detail. If this were an interview she'd be taking notes.

"Well then things got kinda sad and weird 'cause he asked about my hydrophobia and if it was related and then I just…," the girl stopped, looking down at the ground. "I didn't wanna talk anymore. Not about that. Not now. S-so I had us go back with you guys and…he just looked so awkward and out of place while we were walking back. I thought maybe I said something wrong? That, and the bastard is way too damn tall for his own good, I had to half jog just to keep up with the friggin' bean stalk!" That got April to giggle a little.

During Nixie's pacing rant she moved to sit backwards in a swivel chair by her desk as the girl retold her stories. Most nights she preferred to work in the living room, where everyone was. Just to have that nice presence of another person being nearby rather than working all alone with nobody there. That was always nice too, but having a quiet person nearby who you could call on for advice now and then was better. So long as they were quiet. Unlike now.

"Then I just…reached out and grabbed his hand? I don't know WHAT gave me the dumb idea to do that but I just did and…he didn't pull away? He even kinda…held it back." Nix bit her bottom lip, groaning. "God, his hand was huge! Like I'm serious, my hand just disappeared in his and it. Was. Awesome! They were rough and strong but also really gentle and warm and I just…I just didn't wanna let go? Then you know how dinner went."

April smiled, lifting her chin up onto her folded arms on the back of the chair. "Hell yeah I do. You guys were practically inseparable. You sat next to Donnie the whole time. Even when Mikey stole you away to play video games that boy was never far."

"Really?"

"You didn't notice? He was watching from the doorway the whole time. I think Raph teased him a little about it but unless you were going to the bathroom, he was close by all night. I think Splinter noticed too. If he hasn't gotten it already by now, I have a feeling he'll be giving Donnie a recap on… _the talk_." April waggled her eyebrows, a devious grin taking up half of her face. "If ya know what I mean~."

"Oh my gooooood shut uuuup!" Nikita fell back on the couch; face bright red and hiding it under a new pillow. "I haven't even gone out with the guy let alone kissed him! What makes you think we will be doing any of _that_ kinda crap anytime soon, huh?"

"Hey, I'm just sayin'! You're both teenagers, you're both totally into each other, neither of you have done the do before…have you?" She looked at Nix, one brow raised questioningly.

"Good _god_ no! I haven't even had my first kiss yet."

"So if you kiss Don it'll be your first?"

"…Yeah…"

"Oh my gooood!" April grinned. "Your first kiss is gonna be with a mutant ninja nerd!"

"Shut up!" Nixie's ears had started to turn red with how hard she blushed, throwing a pillow at her roommate. "I need to go take a bath."

April just laughed, pulling the pillow off her head. "You know, I still find it weird you're terrified of water, but take long baths. What's even up with that?"

"This is totally not the same thing. It's a bath, not…everything else. I can deal with this." The girl huffed, grabbing her towel. "Just…shut up. If you need to do anything in there do it now."

"Yeah yeah, I know the drill. You take a bath, bathroom goes on total lockdown. Nobody in or out. I know!"

* * *

Things continued much like that for the next few weeks. School started up and Nikita became busy with schoolwork, landing a job at a small cafe on her route to-and-from campus. Sometimes she stopped by the lair or Donnie would come over to help with homework or studying. He ended up just giving her the cube, smiling when he saw she'd finished another side. What he didn't know was that she kept it on her nightstand right next to her bed at night and kept it in her bag when she went out.

April however, was scratching her head over the latest story to cross her path. Stories of some kind of sea creature in the Hudson River started popping up all over the place. The most anyone had on it were sightings of a shimmery purple tail belonging to an unknown aquatic entity. Regrettably most of the reports were statements from people seeing it late at night, almost all of them drunk or high, maybe two or three actually being sober. Some claimed it was an alien from the event earlier that year, others thought it was a government experiment, most thought it was just a hoax. Others were saying mermaid.

"Seriously? A mermaid?! Even if they existed why the hell would one be in New York City anyways?" April rolled her eyes, going through witness statements on her laptop. Behind her Nixie choked on her ramen, quickly wiping away the spill with one of the towels she always had close by.

"A-are they sure it's a uh…mermaid?"

"No, only a select few and it's completely ridiculous. Nobody's seen anything but the tail yet _someone_ decides to spout some nonsense about it being a mermaid?" The woman groaned and rolled her eyes for the millionth time since getting the assignment. "There are no mermaids in New York. California maybe, hell Florida totally, but New York? Even if they were real, New York is the last place you'd find a fuckin' mermaid."

While April turned back to her work, Nixie coughed and shifted uncomfortably in her seat.

After that, the sightings almost completely stopped. Another month came and went. Nothing. There was still a drunk or two saying they saw it, but the stories were never consistent and some happened supposedly within minutes of each other and on completely separate ends of the city. The story fell apart and was left for conspiracy papers to pick up the leftovers.

Mikey was the first to see it in the sewers. It was near the storm drains where water from the Hudson filtered in and out, the deeper sections that weren't filled with sewage and had actual, cleaner water.

He was just boarding through some of the old pipes and tagging a few spots near their old home when he swore it felt as if something was watching him. Worried it might be Foot surveillance, he turned with weapons drawn. In the water nearby he heard a splash and rushed over in time to see a galaxy purple tail, fading into pink at the tip with shining star-like scales ducking under the surface of the water.

Being who he was, he couldn't wait to tell his brothers of the incident. None really believed him, but also saw no reason for him to lie. The sightings had all been in the Hudson, so why suddenly in the sewers?

Raph was the second to see the tail. This one was closer to the actual lair and hardly a week after Mikey reported seeing it. He was blowing off steam with a walk through the tunnels. It was too early to go to the surface and as much as he'd love the fresh air, he had to settle with the sewer.

The red turtle had been spinning his sais. A rat running under his foot caused him to flinch back and startle, cursing. One of his sais slipped from his hand and sank into the murky waters below. "Shit…" He stared into the still rippling water. Would he be able to find it if he jumped in now? He could hold his breath a long time, just like his brothers, but even they couldn't see in water like that.

Just as he was about to give up and think up a way to apologize to his father for losing one of his weapons like that, there was a splash and a clink on the ground behind him. When he turned, a human hand darted back under the water's surface, quick movements disturbing the surface and a tail matching Mikey's description dove below. He stood there for a good five minutes, staring at the spot where the tail disappeared. Had that really just happened? He was about to chalk it up to a hallucination when he looked down. In a puddle of water where the hand had disappeared was the sai he dropped.

* * *

It took an immense amount of explaining to the others but they were eventually convinced that something, mermaid or no, was roaming the Hudson and sewers in their area. Obviously it was some mix between human and fish. Had the Foot experimented on another human like Bebop and Rocksteady but it went wrong? Could this have been something from Kraang's ship that was lurking around?

"I don't think it's dangerous." Raph stood next to Mikey, watching Leo and Donnie as they discussed the matter. "There haven't been any reported attacks, no missing persons in the area, and with Mikey it was only watchin' him. Then fer me, it just gave me my sai back. I think it's just curious."

"That's surprising coming from you, Raph." Leo rose a brow. "I agree, but it's still gotten too close to the lair for comfort. We should at least figure out what we're dealing with."

"You think it's really a mermaid?" Mikey leaned closer, unable to hide his smile. A real mermaid! This was like something out of one of his old comic books!

"We can't be sure, but it could be possible that old mermaid legends and mythology did derive from something. If it's not from Kraang and it's not a mutant, it's entirely possible that whatever this is could be something more…ancient in nature." Donatello looked up from the notes April sent him. He needed all the research and information he could get. "I agree that this doesn't seem hostile, but we still need to remain alert."

Splinter stood apart from the brothers, a look of concern on his face. He couldn't stop his sons from searching without raising suspicion. Sighing, he stepped forward. "My sons." All four turned to address their father. "I would advise you do not go looking for trouble. I understand the need to protect our home, but you must remember not to focus all your energy on a single point while so much else goes on around you."

"Father…?" Leo tilted his head, confused.

"What I mean to say is, do not go looking for a fight where there is none. You have said that this…fish person has only recently been seen near our home?"

"Yes." Donatello pointed to a holo-map he'd set up, red dots showing where the creature had been reportedly seen in reports and orange in the places by their brothers, one green dot being their home.

"Hmm...I do not see a reason for concern. So far this creature is close, but keeps its distance from our home. Whether it knows we are here or not, it must recognize the security protocols you have in place, Donatello. It has been careful to avoid the safety system you have in place." He carefully pointed to the closest dot. "Even here, it has stayed just outside of your sensors and cameras."

Donnie hummed, looking over the map and zooming in, the security field he'd set up now highlighted in pink. "Hmm…you do have a point, sensei. However, we've only seen it two times. That's…not exactly much to go off of."

Leo stepped in. "Alright, so we go about business as usual. But stay alert, and if you see it, report to me or Donnie so we can get an idea of just how close it's getting. If Master Splinter is right and it's giving us our space, we may be able to assume it could be a possible ally. However, it's still seen us. We need to find this thing and try to talk with it, see what it wants." The others nodded, Mikey looking particularly excited while Donnie had a new curiosity in his eyes. This was a new thing to discover and possibly study.

Splinter kept an eye on his sons while pulling out his phone and sending a message to Nixie.

 _ **You need to be more careful, my child.**_

There were a few minutes of pause after the message was read.

 _ **I know…**_


	6. Movies in the Sewer

**Chapter 6: _Movies In The Sewer_**

Sightings of the…mermaid, for lack of a better name to call it (also Mikey wouldn't shut up until they agreed it had to be a mermaid and nothing else), all but stopped soon after Raphael's first sighting. It was rarely seen since and even when it was all they ever saw of the thing was a bit of purple shimmering in the murky water before darting away or a tail splashing right before it dove deeper to depths in which they couldn't see. Even Raph was beginning to question if he'd even seen the human hand at all. It was impossible, but how could a regular fish grab his sai and bring it back up like that? Maybe it was just a big…smart…fish? It was certainly intelligent enough to avoid all of Donnie's security sensors…or just lucky. The creature stayed away from their security perimeter and mostly stuck to parts of the sewer that were the closest to the river.

As it got colder, the sightings lessened even further into non-existence. Donnie theorized that it might hibernate in fall and winter until the weather became warmer. After all, where else could this thing go? It was aquatic and wasn't like it was going to sprout legs and walk to stay where it could be warm. Mikey worried it could be trapped in the river and unable to migrate to warmer climates, but with the fish-like creature keeping its distance from not only the media but them as well; the theory couldn't be tested or researched.

"So we can't do anything? Like…maybe set up some kind of heater in one part of the sewers or whatever?" Mikey suggested once.

Donatello sighed, pushing up his glasses. He'd been spending too long at the computer again, researching the many theories on the existence of mermaids and any sign that maybe; just maybe, there was some kind of intelligent fish that could explain all of this. So far all he came up with were nothing but fairy tales and dead ends. All of it was superstition and folklore. "We could, but if this fish-"

"Mermaid."

Don sighed. "Mermaid…is as smart as we've been lead to believe, it may see it as a trap and avoid the heater altogether. If that happened it would likely find somewhere else and we may never find out what's really going on. I'm sorry Mikey, we just can't risk it." Defeated, the younger turtle left the lab once again. With all this searching for the finned creature he spent more and more of his time with Donnie in his lab.

* * *

October was just around the corner and already a few people were beginning to bundle up. Even Donatello and his brothers started wearing a few more layers with their gear and cranked up the heat in the lair.

Just after October started, Nixie got out on fall break. It gave her more time to spend with the boys, as well as extra hours at the café for the upcoming holidays. She tried spending as much of her free time as possible with her friends.

On a particularly chilly evening the girls were invited down for hot chocolate and movies, Splinter offering for them to stay the night. Nixie seemed a bit wary of staying the night in the sewers, but after much convincing from April and Mikey's combined efforts, and some stuttered encouragement from a blushing Donatello, she was in. The girls would be set up in the living room. Splinter trusted his boys and the two girls, but he refused to allow any of them to sleep in his son's rooms. He was still the father, last he checked. Mikey immediately wanted to put on something with horror, but his brothers teased him about having nightmares again if he did. When he looked to Nixie for help in the hopes that his newest human friend might like getting scared just as much as he did, she had already wrapped herself tight in her blanket and scooted as close to the nearest person as she possibly could. Much to Don's dismay, that ended up being Raphael.

She practically whimpered as she ducked under his enormous arm. "Nuh uh! Now way in hell! No scary movies or I am soooo out!" The little glare on her face was directed at a certain orange troublemaker.

Raph looked up and gave Don an apologetic glance as the tiny human pinned herself to his side, clinging to a bicep that was so much bigger than she was. The taller turtle sighed, giving his brother a silent okay. It was his own fault for being a coward, using the excuse of getting popcorn to leave for a moment rather than take the seat beside Nixie like he'd originally planned. While he did his best to hide his childish pouting, he was secretly grateful to his older brother for acknowledging his interest in the human female. Raph didn't need his permission to comfort her when she was scared. After all, she wasn't exactly his.

"What?! How can you not like scary movies? I thought you loved all the creepy stuff like monsters and bats and Halloween and junk!" Michelangelo whined, giving her big pouty puppy eyes.

On anything else she would fold in a second, but not this time. "I do Mikey, but I can't stand horror and gore…that stuff's different. I won't be able to sleep for weeks! You know I'm already afraid of the dark…" The girl whined, squirming ever closer to her red turtle protector, who carefully wrapped his arm around her shoulders and let her cling as much as she wanted. Next to him she looked like a small child.

"It's true." April added from behind her mug, downing a few more sips. None of this fazed her anymore. "She might love all that monster stuff but as soon as you make it scary or they start killing shit she starts crying. When we were kids she wouldn't watch the Casper movie, you know the one with that girl and her dad who move into that old house?"

"What?! Casper isn't even scary!" Mikey's eyes widened, swiveling his head back to the girl in question.

"Hey! I wasn't scared of Casper! His uncles were scary and that part where they all possess that girl's dad was terrifying when we were little okay?" Nixie squeaked, jabbing a finger at April. The yellow reporter just smiled behind her mug and shrugged, feigning innocence.

Raph chuckled, moving his free hand across to ruffle the teen's short hair. "At's okay lil sis, we'll protect yah from all the big bad ghosties," he teased. He only laughed more at her indignant huff and the inevitable kick to his leg.

"Shut up, we're the same age…jackass." Now he was just cackling.

Eventually, Mikey conceited, settling instead for some Halloween classics such as Hocus Pocus, Halloweentown High, and Nightmare Before Christmas. Of course, since it was mentioned, Casper was also added to the list, much to Nixie's pouting.

Each one of them finally settled into their spots. Splinter took the old Lazy Boy near the couch, which was occupied by April who got sandwiched between Raph and Leo. On the floor in a nest of blankets were Nixie and the other two. Each had bowls of popcorn, mugs of hot chocolate or cans of soda, and of course some pizza. Splinter had hot chocolate for once rather than his usual cup of tea. Nix couldn't help but giggle at the cocoa foam that got stuck to his whiskers.

During Casper, Raph made sure to poke fun at Nixie whenever the uncles were on screen. _Especially_ during the possession scene.

"Hey! I'm not scared of it anymore but you gotta admit it's pretty freakin' nasty. I-I mean look at that! Ugh…I think I'm gonna be sick…" She set her mug to the side for a while, unable to consume much of anything for the moment. Instead she leaned on Donatello, who turned a little red when she nudged her way under his arm like she had earlier with Raphael on the couch. He swallowed a lump in his throat, shifting to move a little closer and make it more comfortable. It seemed to work as she settled in with a content little sigh before jumping up in shock with a loud gasp.

While shifting, they'd pulled a blanket and spilled one of Mikey's sodas all over her leg. Of course, he'd put it on the floor rather than up on the table right next to him. "Oh, I am so sorry, let me help-"

He didn't get much time to try helping. For a second Nixie tried using a spare blanket to wipe at her leg, but quickly seemed to come to the conclusion that it wasn't enough. Before he could stop her she was up and rushing for the bathroom. "…you…" His shoulders slumped. _So much for that idea. Way to go, Donatello. Real smooth spilling soda all over her._

Splinter, regrettably, had already fallen asleep in the chair a few movies back and missed the commotion. Thus, he was unable to console his self-destructing son as well as stop Mikey from going to check up on their friend. April encouraged him to go while she helped the others clean up the spill. "You go check on her. She always freaks out and locks herself away for a while after this kind of thing." She got up to grab more paper towels and put the blanket in a wash.

 **. . .**

Mikey walked up to the bathroom door, tapping on it before opening, not waiting for a response. "Nix? Hey are you okay in-…there?" Before him, looking like she'd toppled over the second she shut the door, now staring up with wide and frightened eyes, was Nixie. On the floor. With a large, purple-pink gradient fish tail in place of her legs.

His jaw dropped, eyes going wide as the pieces slowly clicked into place. This couldn't be happening, right? He had to tell his brothers! Before he could say anything or call for them she moved to stop him, only to flop over. The movement itself was enough to give him pause. "Mikey please, d-don't!" He stopped, excited grin fading. She looked terrified. He knew it wasn't fear of him, but seeing it on her face as she looked right at him reminded him of that night at the police station. Being called a monster and a freak. She didn't think they'd really do that to her, did she?

With a quick look behind him, he slipped into the bathroom and shut the door behind him, locking it this time. "Nix? That's uh…i-is this…real? Are you…?" Mikey stopped, wanting to hear the words come from her.

"Yes, Mikey. I'm…" she sighed, looking like this was the toughest thing she'd ever done. "I'm a mermaid…"

The terrapin squealed and bit his lip, smile returning. He knew it! Well, maybe not that it was Nixie but he knew there was a mermaid! Mikey dropped to the ground next to her. "How long have you been a mermaid? Where did your legs go? Does this happen all the time? What happened to your pants? Wha-"

"Whoa whoa, slow down! Chill. One thing at a time!"

He stopped, settling down beside her. He kind of wanted to touch it, see how the tail felt, but worried that might be an invasion of privacy. This was still his friend Nixie, not some new toy or thing he found. "…Is this why you're so afraid of water?"

Nixie sighed, rolling over so she could sit propped up on her arms. It didn't look very comfortable. "I've always been a mermaid, my legs uh…kinda merge to become my tail? I don't really know. I'm…actually not sure where my pants went, we've never figured that out. And only when I get wet so…yeah, this is why I'm _afraid_ of water." She used one hand to make finger quotes around the word afraid. "My dad pretends to have an allergy to water."

"Wait, so your dad is a merman? What about your mom? Is she-"

"No, she's a human. And before you ask it's more common than you think actually. And yes, she does know. Kinda hard to miss when you go to give your baby a bath for the first time and she grows a tail. Well…it's also how they met but I'll get to that later." She waved her hand, looking to Mikey. "Mike, it…it's forbidden to tell others what I am. There are a few exceptions, but you're really not supposed to know about this. No one does, not even April!"

Michelangelo's face paled, smile dropping. "Not even April? You're…you're not gonna leave are you?! You can't go!"

"What? No! No no no, of course not! It's not that bad, really. I just…you need to promise me you won't tell anyone. Ever. Not even April."

"What about my dad?"

"Splinter? Oh uh, he's fine. He…kinda…already knows?"

"WHAT?! How long has he known?!" The turtle stared at her.

"Uh…apparently since I was a baby and he was still just a lab rat? I…don't really know how he knew? I think he mentioned something about smell so uh…yeah, that." The girl shrugged, moving and shifting her spot on the floor. "Look, I promise to explain everything later and answer whatever questions you have but first can you help me clean up? My tail feels all sticky and gross from that soda can you made me spill."

He popped up right away, grabbing a towel and a wet rag. "Right! Right, um…one more question?"

She sighed and rolled her eyes with a light smile. Classic Mikey. "Sure, one more question. What is it?"

"Can I touch it?"

* * *

What normally might have taken much longer on her own only took a matter of a few minutes with Mikey's help, getting Nixie to soon walk back into the room with a normal set of very human legs and wearing a spare pair of pants from her bag. Mikey followed not soon after, letting April know he added the soiled jeans to the load of laundry. The first thing she noticed was Donnie, sitting on the floor and avoiding her gaze.

"S-sorry, I…kinda got a little freaked out and needed to clean up. I'm sorry for running out like that. Are…you mad at me?" She gave him an awkward, apologetic smile.

The purple turtle snapped his head up at her apology. "What?" Why was she apologizing to him? He should be the one apologizing! He spilled soda on her! "N-no! I-it's not your fault, i-it was my fault I should have been more careful I-" He was stopped by a small hand pressing itself over his lips.

Nikita was looking at him with soft eyes and a warm smile. Don's heart felt like it was going to jump out of his chest. "Relax Don, it was just an accident. You didn't do it on purpose." She pulled her hand away and sat next to him again, returning to the spot where she'd been snuggled up before. "Now, tell me what I missed."

All of his worries melted away; all of his doubts and concerns vanishing for a little while. He just wrapped his arm around the girl, pulling her close as they finished their movies and he got her caught up. Off to the side, Mikey moved to place his new can of Orange Crush on the floor, but stopped and placed it on the coffee table instead. Behind him, a now awake Master Splinter raised a brow at his son's actions, looking to Nixie curiously.


	7. Mornings Are Bittersweet

**Chapter 7: _Mornings Are Bittersweet_**

Splinter left his room the next morning to find everyone fast asleep in the main living area of the lair. His sons and their two human allies were all spread out on the couch, in chairs, or in a nest of blankets and pillows on the floor. The TV still played the home screen of whatever movie they'd unfortunately fallen asleep to. The old rat couldn't help but chuckle and smile as he looked at all of their sleeping faces.

Raphael was sprawled out on the couch, snoring and with a blanket only half covering his body. Using his chest for a bed was April, a pillow under her head and a mess of dark hair all over the place. Raph's arm was wrapped around her middle to keep her from falling off the couch. Even in his sleep Raph was always the protector, doing his best to make sure none of his family got hurt. Having taken a spot in Splinter's Lazy Boy was Leonardo. His hands were gently folded across his middle while his head lolled forward onto his chest. It looked more like he was meditating or contemplating something than sleeping. On the floor, lying on his stomach on top of a mass of pillows and a teddy bear was Mikey. He didn't snore as much as Raphael, but he still snored.

Leo stirred in the chair as Splinter moved to see where Donnie and Nikita might be, causing the rat to pause. The eldest turtle lifted his head slowly, blinking the sleep from his eyes as he looked around for the small disturbance that had awakened him. Splinter smiled as Leo looked to him and relaxed again, only to move to stand. "Did I wake you, my son?" The turtle shook his head, standing and stretching out his back. He was awake, but still groggy.

"No dad, I was just about to get up anyway." Leonardo rubbed at his eyes, giving his dad another smile. "Want me to make some tea?"

The old rat shook his head, motioning for his son to sit back down. "Sit, I will make the tea." He started walking to the kitchen only after Leo sat back in the chair once again. "Have you seen your brother Donatello? I don't see him or Nikita."

Leo looked over at the others sleeping with tired eyes. He then stopped and smiled. Without saying a word he motioned the old rat over. Curious, Splinter came over to his son's side as quietly as possible. There, bundled up in the very middle of the blanket nest and almost hidden from view, Nixie and Donnie both lay curled up under the covers. The scene brought a smile to both their lips. The two were cuddled up and fit together like two puzzle pieces. Nixie was curled up against Donatello's chest, her arms holding one of his captive against her chest. Donnie himself was almost completely wrapped around her smaller body in a tangle of limbs, face buried in the hair atop her head. Both were fast asleep.

Splinter looked at the two with a knowing fondness. "Let's wake those two last."

 **. . .**

It did indeed seem that Donnie and Nixie were the last to awaken, if his family's phones were any indication. By the time he woke up Mikey had already taken ten pictures and two videos, each brother and even April taking plenty of photographic proof for later use and possible embarrassment, if not blackmail. When they saw him start to finally stir, they all fled the scene of the crime, recording from other sides of the lair to get each and every bit of his impending reaction.

Donnie woke slowly, reluctant to leave the gentle hold of sleep. He was warm and felt a warm presence in his arms, one he was reluctant to release anytime soon and pulled a little closer to nuzzle his face deeper into whatever soft object his beak was buried in. The smell alone was like heaven. Lavender and honey, something that smelled like cookies or baked goods, and….salt? No, more like the ocean itself. It was an odd mix, but it was familiar and he wanted to envelop himself entirely in that scent alone. He sighed into the soft thing, not yet opening his eyes until the warm object moved and groaned. _It groaned? What was warm and groaned?_ Suddenly his eyes snapped open. The sleepover! April and Nixie came over to watch movies! They must have fallen asleep!

The world was blurry without the aid of his glasses. Where were they? The purple ninja squinted, untangling an arm to pat at the ground around him. He knew they weren't on his head, he'd woken up in the middle of the night and taken them off so where….ah! Reaching up onto the nearby table he found what he was looking for, placing the glasses on his face and blinking profusely. It was still a little fuzzy from the haze of sleep, but at least he could see now. Carefully, he looked down at the warm thing in his arms and froze, blood turning cold as his cheeks felt all too warm. The warm thing he'd been contently cuddling a moment ago? That was Nixie. Oh god, this was terrible! Well it was actually kinda nice…but also terrible! How long had he been cuddling her? She wasn't awake yet, was she? He didn't have his goggles to scan her vitals, but for the moment she at least appeared to still be fast asleep. Her breathing was slow and even, a peaceful look on her face as she remained curled up against his chest.

He sighed, relaxing ever so slightly. Now that _that_ panic attack was over, he took a moment to get a better look at the small human in his arms. After all, logically his siblings must already be awake and have a million pictures by now, most of which he'd need to somehow confiscate or delete at some point. He may never get a better chance to look at her while she slept ever again.

Needless to say, her hair was a mess. With a mix of his sleepy nuzzling and whatever movements she made in her sleep, she had the wildest bedhead he'd ever seen. It was all over the place and stuck up in every direction. She probably had at least five cowlicks. Her face was what he mostly focused on, the way her eyes were softly closed and he could see her thick eyelashes a bit better. He never noticed how long they were until now. No wonder her eyes always seemed so wide. Her mouth was slightly open and he could hear her breathing. It wasn't quite a snore, but he could hear the air go in and out softly. How could something so very simple still seem so amazing to him? Part of him wanted nothing more than to go back to sleep and pretend nothing happened, to take the risk of what might happen should she wake up just for a few more minutes of holding her. Another part wanted to kiss her. Her head, her eyelids, her cheeks, every inch of her face. Maybe even her lips to see if it would be anything like those fairytales she loved so much. For a few moments he leaned closer, heavily considering it, but paused. No. He shouldn't. Not like this. Not while she was asleep. If he was going to kiss her for the first time, it should be while she's awake and can process, while she can give him a proper response. He needed to wait. With a sigh, he settled for lightly pressing his forehead to hers and taking one last whiff of her scent, committing it to memory.

Being ever so careful, Donnie pulled himself from her arms. When her face contorted in discontent and her hands tiredly searched for the missing presence of his body next to hers he felt a tug at his heart. He wanted nothing more than to comply, to go back and pull her into his embrace once again. Instead, he replaced his form with a few large pillows that still held some heat and wrapped her up in more blankets, watching her face fall back to a peaceful slumber. "Sleep tight, princess." He brushed some hair from her face before standing up, navigating his was around the pillow nest on his way to the kitchen for a much needed cup of coffee. He wasn't sure how much longer he could pretend to just be friends after this. Somehow, he needed to tell her how he felt. No more stumbling and beating around the bush.

 **. . .**

Raph watched his younger brother sadly as Mikey recorded the whole thing. It wasn't for blackmail or gentle teasing anymore. The pictures maybe, but this? This would be stored away. For what, Mikey wasn't sure. He just knew this might be important later. Somehow.

For Raph, his heart nearly broke as he watched all of the emotions on his brother's face. It started with drowsy bliss before warping into realization, fear, then just…sadness. Longing. What had started out as cute and a little funny to watch had become painfully bittersweet. His brother had fallen and fallen hard. It almost hurt to watch the two of them together, each secretly pinning for the other but too scared of rejection to notice that they both felt the same. It made Raph frustrated. He wanted nothing more than to go up to the two of them and scold them for being so blind, to lay it all out as clear as day for both of them, but he knew he couldn't. This was something you just couldn't force and it made him all the more furious. Some part of him wanted to lock the two nerds in a room until they admitted their crush on each other, but a larger part of him knew that would only be worse.

He sighed, shoving at Mikey and the others to clear out as Donnie made his way over to where they hid in the kitchen. His brother didn't need them crowding him and making him nervous or upset. "C'mon guys." Right now he could use some space, not obnoxious teasing and jabs to his ribs with comments about getting cozy with a cutie from Mikey.

* * *

April made certain to show Nixie every single picture from the sleepover. From the silly moments to her being snuggled up to Donnie in her sleep. She left out the videos of Donnie waking up and calling her princess. The video may not have picked it up, but Raph had made her and Mikey promise to keep those to themselves or delete them entirely.

At the sight of her and Donnie cuddled up and fast asleep in the lair Nixie became a blushing mess. She hid her face in her jacket, a pillow, anything she could as she kept looking back to the picture before hiding all over again to blush and squeal. It took a while for her to finally stammer out to April if she could send her one of the pictures. Donnie's sleeping face was just so cute! If she could she'd put it as her phone background, but that was too much of a risk.

Much to Donnie's dismay and annoyance, Mikey and Nixie became thick as thieves since movie night. He kept telling himself it was just Mikey being Mikey and that he was just excited to have a human friend their age. It was nothing. That of course, didn't stop him from getting just a little jealous when the two spent time together on their own.

 **. . .**

Mikey sat on the stone walkway of one of the sewer tunnels, Nixie relaxing in the water next to him. She held her upper body up on the floor next to him while the lower half remained submerged in the water. Every now and then they met up like this in secret, in one of the farther tunnels. She didn't swim much in the Hudson or the water ways close to the lair, it was too dangerous and too cold. When they met up Mikey brought a small water heater to keep her warm.

"So Nix, tell me again why you can't just…tell the others? I mean I understand not telling the world and I get keeping it from April as kids but you can trust us, right?" Mikey gave her a quick glance. "I mean, we're pretty good at keeping secrets and none of us would let anything happen to you. You're part of the family. One of us."

Next to him, Nixie glanced down and sighed. "I…I know, Mike. I know. I…I know I probably could but…I'm still scared, you know? Heck, you and Splinter are already a huge risk." She lifted herself up to sit next to him, her tail gently moving the water around. "We're not allowed to let other people know we exist, to be seen. The only exception is supposed to be the person we intend to spend the rest of our lives with, who we plan to mate with and marry. Sometimes it's only the mate; sometimes the whole family learns the secret. It honestly depends on the situation. My dad got lucky with my mom and her family. She met him completely by accident and eventually they fell in love and got married. They were best friends who got married and lived happily ever after and had a kid. The end…mostly." She sighed. "It's forbidden to tell friends, no matter how close they are. April's dad was my parent's best friend and he never knew. Nobody did."

"But we're different, Nix! That rule is supposed to be with humans, right? Well last I checked we weren't human, right? That's gotta count for something? And April kept our secret so I know she'd keep yours too!"

Nixie ran a hand through her wet hair, hissing out a breath through her teeth. She knew Mikey meant well, but it just wasn't that easy. "I-I know I just…it's more complicated than that. I-I don't know what the rules are for someone who isn't human but…isn't mermaid either? Like if we happen to meet another of our own kind its fine and all but…there's never really been anything with somebody like you guys. I could ask my dad but…I don't think he'd know either? It's just…never happened before, you know?" With another sigh she pulled her tail up against her chest, leaning on her friend for support. "I need more time to figure it all out."

The orange ninja wrapped an arm around her shoulders, pulling her a little closer. "Yeah, I get it angel cakes. I get it. It's not easy bein' different." Next to him the mermaid girl sighed and nodded her head. "Just know that whatever you end up deciding I'll be right there to back you up."

"Thanks, monkey." Nixie smiled, giving his side a hug, giggling as he returned it with an enthusiastic squeeze.

Mikey grinned and quickly scooped her up. It was a little harder to hold her with the long tail and slippery scales to work with, but she was just as light as she was when human…well almost. The tail did add a pound or two. He only smiled wider as she laughed and held on tight. "Anyway, back to our original agenda. What were your plans for Halloween this year?"


End file.
